Filling needles are used for example for filling containers with fluids for pharmaceutical or cosmetic use. In particular, the filling needles are for this purpose firstly introduced through an opening into an interior space of the container, and, during the filling process, are preferably gradually retracted out of the container in order to permit filling of the container even through small openings and without spray losses.
In filling installations, it is possible, for this purpose, for one or more filling needles to be provided in order to fill a corresponding number of containers simultaneously.
An example of a device and a method for filling containers is presented by document DE 10 2006 019 518 A1. The document proposes a device and a method for filling containers, which device has at least one filling device which, by way of a filling needle, supplies liquid to at least one container to be filled, wherein the filling needle is used to completely fill the container. Furthermore, it is sought to provide a drive device which moves the filling needle during the filling process.
Furthermore, for example, document DE 42 27 980 A1 presents a device for dosing a medium into a container from at least one nozzle or the like which is connected via at least one line to a dosing device which is connected to a storage container. Here, it is the intention for the nozzle to travel along with the container during the dosing process in a manner dependent on the activity of a conveying device.
Furthermore, document DE 92 07 051 U1 presents a device for introducing liquids of relatively high viscosity into a storage container for the liquid, from which storage container a line leads to a pump which opens into a filler neck. Here, it is the intention for a shut-off valve to be connected into the line upstream of the filler neck, wherein the shut-off valve is intended to be a solenoid valve, the opening duration of which is variable. It is the intention for the solenoid valve to be actuated by way of an adjustable timing relay.
Thus, in general, solenoid valves are proposed for shutting off or opening up lines in an actuable manner. The solenoid valves are in this case always arranged between a storage container and a filling device. Further such solenoid valves that are generally arranged in fluid circuits are presented for example by the documents DE 32 27 616 A1 and DD 15 98 41 A1.
A plunger may be provided which closes off or opens up an outlet opening of a filling needle in order to precisely dose the liquid quantities with which filling is to be performed. Since the plunger element is arranged directly at the outlet end, it is thus possible to prevent follow-on running or dripping of liquid quantities. In filling needles, however, it is simultaneously the case that only a small structural space is available at the outlet end, such that actuating elements for moving the plunger element must be provided remote from the outlet opening. In the prior art, these are actuators which are coupled to the plunger by way of a bar element which extends in the interior of the filling needle and parallel to the longitudinal axis thereof. The actuators are sealed off with respect to the fluid chamber by way of seal packs. Nevertheless, the filling needles must be cleaned at certain intervals in order to be able to reliably adhere to requirements that may exist with regard to clean space conditions. For this purpose, the filling installations must be stopped, and all of the filling needles must be dismounted and cleaned. Correspondingly, the cleaning of the filling needles is, owing to the downtime of the entire installation, associated with a relatively high cost outlay.
For example, from documents DE 10 2010 030 175 A1 and DE 10 2012 206 262 A1 nozzle needles for the injection of fuel are known, in the case of which a solenoid armature arrangement is moved by way of a selectively energized coil. This however necessitates a supply of electrical current to a nozzle needle of said type, and may necessitate mechanically relatively cumbersome arrangements with spring packs which preload the nozzle needle into a closed state in order to ensure reliable operation.
There is therefore a demand for an improved filling needle for filling a container, which filling needle requires less outlay for cleaning and maintenance and, at the same time, maintains a simple construction.